Effect of Subject Rotation on Assessment of Esthetic Dental Ratios: A Simulation Study

Objective. This study aimed to find out the change in esthetic ratios during rotation of patient’s head using a simulation. Materials and Methods. A plaster study model was photographed placing its midline along the long axis of the camera. Then a series of photographs were taken by rotating the model each degree till 10° on both right and left sides. These photographs were digitally measured and the ratio of the maxillary anterior teeth at zero-degree rotation was compared with that at various degrees of rotation. Results. As the model was rotated to the right side till 10°, the ratio of the right lateral to central incisor gradually decreased while the ratio of the left lateral to central incisor gradually increased. However, the ratio of the canine to lateral incisor on both sides gradually increased. Similar results were obtained when the model was rotated to the left side. The ratio of the lateral to central incisor deviated from the acceptable range (±10%) when there was rotation of more than 7°, whereas the ratio of the canine to lateral incisor was within the acceptable range till 10° rotation on either side. Conclusions. Rotation of the model by more than 7° leads to a substantial change in the esthetic ratio

Orthodontic correction of severely rotated maxillary central incisor in a diabetic adult

Background: Orthodontics has recently seen an increase in the number of adult population seeking treatment. Financial dependency, increasing awareness and availability of service can be the reasons behind this rise. Though, clinical myths regarding duration, effectiveness of treatment, associated systemic conditions still exist, these should be of no concern and with adequate monitoring and procedural modifications, conventional orthodontic treatment is possible.Case description: A 58 year old Type II diabetic male presented to orthodontic clinic with unesthetic gap between upper front teeth. The history revealed extraction of painful mesiodens. On examination, the patient had Class I molar, canine and incisor relationship. 21 was rotated with 5mm of space between central incisors. Fixed orthodontic treatment was planned after physician consultation regarding his diabetic condition. Bondable buccal tubes instead of bands were used in first molars, 0.022” Roth brackets were bonded on other maxillary teeth. The wire gradually progressed from 0.014”NiTi, 0.016”NiTi to 0.018”SS. Lingual button was attached on the labial and lingual surface of 21 to apply couple. After the correction of rotation of 21, remaining space closure with esthetic contouring of 21 was done. Maintenance of adequate oral hygiene was reinforced throughout the treatment period. Fixed lingual retainer was bonded and pericision performed to retain the achieved result.Conclusion: Orthodontic treatment can be carried out in diabetic adults with good glycemic control to achieve esthetic results; however, measures for maintenance of adequate oral hygiene should be undertaken. Interdisciplinary approach involving restorative procedures can enhance the esthetics achieved.JCMS Nepal. 2015;11(3):30-34</p

New regression equations for mixed dentition space analysis in Nepalese mongoloids

Abstract Background Mixed dentition space analysis methods using regression equations, namely, Moyers’ analysis and Tanaka-Johnston analysis are commonly used around the world. However, the applicability of these analyses among different racial groups have been questioned. The primary objective of this study was to assess the applicability of the Moyers’ and Tanaka-Johnston analyses among Nepalese Mongoloids and to develop regression equations for the same population if needed. Methods One hundred (50 males and 50 females) pre-treatment study models of the Nepalese Mongoloid patients undergoing orthodontic treatment were retrieved from the archives of the department of Orthodontics. The mesiodistal widths of mandibular incisors and widths of canines and premolars of all 4 quadrants were measured by a single investigator using a digital caliper to the nearest 0.01 mm. Predicted widths of canines and premolars were obtained using standard Moyers’ and Tanaka-Johnston analyses and then compared with the measured widths. Results The measured widths of canines and premolars were significantly different from the predicted widths obtained from Moyers’ and Tanaka-Johnston analyses. Strong and positive correlations were found between the sum of mesiodistal widths of mandibular incisors and the sum of mesiodistal widths of canines and premolars in males (0.73 for maxillary arch and 0.68 for mandibular arch) and females (0.64 for maxillary arch and 0.79 for mandibular arch). Conclusions The Moyers’ and Tanaka-Johnston analyses did not accurately predict the mesiodistal width of unerupted canines and premolars for Nepalese Mongoloid population. Hence, new regression equations have been developed for this population. However, validation studies should be conducted to confirm the applicability and accuracy of these equations

The morphology and bridging of the sella turcica in adult orthodontic patients

Abstract Background The purpose of this study was to determine and compare the shapes, sizes, and bridging of the sella turcica in patients with different skeletal patterns and genders. Methods It was a cross-sectional comparative study. The samples were divided into three groups according to the skeletal pattern viz. Class I, Class II and Class III, and each group consisted of 40 samples (20 males and 20 females). The lateral cephalograms were traced and the sella turcica was assessed for its size, shape, and bridging. Results The mean length, anteroposterior diameter and depth of sella turcica were 8.13 ± 2.03 mm, 9.60 ± 1.43 mm and 6.40 ± 1.21 mm respectively. The mean length of sella turcica was 7.91 ± 1.52 mm in Class I, 7.32 ± 1.62 mm in Class II and 9.16 ± .2.42 in Class III skeletal pattern; anteroposterior diameter was 9.30 ± 1.02 mm in Class I, 9.15 ± 1.28 mm in Class II and 10.35 ± 1.64 mm in Class III skeletal pattern; and the depth was 6.40 ± 0.92 mm in Class I, 6.07 ± 1.01 mm in Class II and 6.74 ± .1.54 mm in Class III skeletal pattern. There were significant differences in length and anteroposterior diameter and sella turcica between Class I, Class II and Class III skeletal patterns (p = 0.01), (p = 0.01) respectively. There was no significant difference in size of sella turcica between different genders and age groups. Sixty percent of the patients studied had normal Sella morphology. Partial Sella turcica bridging and Sella turcica bridging was seen in this study in 23.33% and 11.67% of patients respectively. Conclusion Sixty percent of the patients had normal sella turcica. There were significant differences in lengths and anteroposterior diameters among Class I, Class II and Class III patients. The larger size was present in skeletal Class III patients

Techniques for Genetic Analysis of Non Syndromal Cleft Lip/Palate: A Review

Abstract The formation of craniofacial structures during embryonic development involves various complex molecular pathways. Disturbances in these pathways either due to genetic or environmental factors may lead to orofacial clefts. Approximately two thirds of the cases are not accompanied by other anomalies and are called non syndromic. The etiology seems complex, but genetics plays a major role. With the advances in molecular biology and genetics such studies are more refined than ever before and various candidate genes have been associated with Non Syndromal cleft lip/palate in different populations. There are various techniques and models used by different investigators across the globe. In this review we intend to describe most common approaches towards genetic analysis of Non syndromic cleft and try to evaluate the merits and demerits of a particular approach